Clock.



L. D. GIDDENS.

CLOCK. APPLICATION FILED MAY 9, 1912.

2 SHEETS-SHEET '1'.

WITNESSES INVENTOR m' I Aflorney cowllu Maria :6 wuummu. n. c.

Patented May- 13, 1913.

L. D. GIDDENS.

Patented May 13; 1913.

2 SHEETS-SHEET 2.

LEWIS D. GIDDENS, 0] WILSON, NORTH CAROLINA.

CLOCK.

Specification of Letters Patent.

Patented May 13,1913.

Application filed May 9, 1912. Serial No. 696,117.

To all whom it may concern:

Be it known that I, Lnwis D. GriDnnNs, a citizen of the United States, residing at Wilson, in the county of Wilson and State of North Carolina, have invented certain new and useful Improvementsin Clocks, of which the following is a specification.

My invention relates to improvements in clocks, and has particular reference to a signal clock provided with an improved form of alarm mechanism therefor adapted to sound at the termination of a certain period of time and automatically re-set itself to sound when said period has again elapsed, the invention being further designed as an improvement upon the clock covered by Letters Patent 990,809, granted to me April 25, 1911.

The leading object of my invention is the provision of an improved signal mechanism for clocks, which mechanism is especially adapted for use in mills where cotton seed is boiled to extract the oil, my device providing an alarm mechanism which can be set to warn workmen at the termination of the period of time which the seed should remain in the vat and thus permit said workmen to occupy themselves with other work instead of it being necessary for them to remain by the vat due to lack of a suitable alarm mechanism which will give warning at the termination of a certain number of minutes.

The further object of my invention is the provision of an alarm mechanism which can be set to give a signal at the end of a desired number of minutes and which will be automatically released after giving said signal and will re-set itself to repeat the alarm when said number of minutes have again expired.

A further object of the invention is to provide a signal mechanism which can be adjusted independently of the time recording mechanism to permit the clock to be used for its common function of recording time without the sounding of the alarm mechanism, and which alarm mechanism can be easily and quickly moved intoand out of operative position when desired.

To attain the desired objects, my invention comprises a ratchet wheel secured on the rear end of the shaft bearing the minute hand of the clock and rotating therewith, and a pawl adapted to be engaged by the ratchet wheel and carried around thereby,

an abutment for engaging and releasing the pawl, an electric circuit associated with the clock and containing an alarm actuated when the pawl engages the abutment, and means for prevent-ing the alarm mechanism from being sounded when desired, the invention further residing in the novel features of construction and combination and arrangement of parts for service, substantially as described and as illustrated in the accompanying drawings.

Figure 1 is a front elevation of the complete invention. Fig. 2 is a rear elevation, partly in section, of a clock equipped with my improvements and illustrating particularly the alarm sounding mechanism. Fig. 3 is a vertical central sectional view taken on plane 22 of Fig. 2. Fig. 4 is a detail perspective view of the clamping collar for the index lever. Fig. 5 is a detail perspective v1ew of the oscillating pawl and pawl bearing plate. Fig. 6 is a detail view of an improved form of tripping cam lever for limiting the movement of the oscillating pawl, and Fig. 7 is a detail sectional view of a part of the signal mechanism, illustrating the means for adjusting same to throw it into and out of operative position. Fig. 8 is an enlarged detail view of the pawl and pawl bearing plate, and illustrating a difierent form of ratchet In the drawings, in which similar characters of reference are employed to designate corresponding parts in the several views, the numeral 1 denotes the clock having the face 2, provided with the customary designations for indicating the time and having the minute hand 3 mounted on the arbor or shaft 4 and the hour hand 5. The shaft 4, has a threaded reduced portion or extension 6, and around the shaft is placed a ring or collar 7, provided with a pair of lugs 8, which pass through openings in the clock casing and are bent down against the clock casing to secure the collar in place.

The numeral 9 designates an arm, secured under the collar, as best shown in Fig. 3,

i and formed with a pointer 10 projecting onto the face of the clock and having an abutment 11 for engaging the pawl or dog 27, hereinafter described. A ratchet 12 is secured upon a collar 13, mounted on the extension 6, which is provided with a screw nut 14, spaced between which and the ratchetwheel is the loosely mounted trip lever 15, formed with the vertical extension 16, terteeth for the ratchet wheel.

minating in the cam shaped abutment portion 17, and having a lateral extension 18, over which passes one end of the tripper rod 19, retained in place by the screw 20, and

a formed at its lower end with the plunger 21,

working in the casing 22, secured to the clock by the barbed plate 23, and having mounted therein the spring 24, the lower extremity of said tripper rod being threaded to engage the ball or knob 25, movable laterally thereon.

Pivotally secured upon the extension 6 is the plate 26, while secured to the outer end of the plate is the pawl 27, having a longitudinal slot 28, through which passes the stud 29, a pair of abutments 30 and 31 being arranged on the plate to limit the movement of the pawl. A curved blade spring 32 is secured to the plate by fastening 33 and bears against the pivoted end of the pawl to force it inward. The plate 26 is further formed with a projecting portion 3 1, to which is connected the wire 35, passing through the binding screw 36, and being grounded in an alarm device 36, a battery 37 being connected with the alarm device and having a wire 38, passing through binding screw 39, and terminating in the contact point 40, mounted upon the clock.

The operation of my device will be readily understood by reference to Fig. 2, from which it will be seen that the ratchet wheel rotates with the arbor of the minute hand, thus making one revolution an hour, if the ratchet wheel contains but 60 teeth, and that the pawl is adapted to engage one of the teeth of the ratchet and thus carry the plate 26 around with the ratchet to contact with the contact abutment 40 of the clock, and thus establish a circuit tosound the alarm, the cam portion of the trip lever engaging the pawl just above the ratchet and the continued movement of the ratchet causing the pawl to ride upward on said cam shaped abutment until it is free of the ratchet, while at the same time the cam and blade spring together will swing the pawl on its pivot stud against the abutment 30, where upon the pawl being no longer in engagement with the ratchet, the spring 41, secured at one end to the clock casing and at the other to the extension 42 of the plate 26, will swing the plate 26 back away from the cam abutment 17 and the abutment 40 and break the circuit to shut oif the alarm, the trip lever being retained against improper movement by means of the abutment 44, carried by the clock, the abutment 11 of the arm 9 limiting the downw rd movement of the plate 26. As the pawl 27 rides upwardly on abutment 17, the blade spring 32 is being compressed to hold the pawl against abutment 30 on plate 26, as indicated in dotted lines Fig. 2. When the coil spring 42 exerts its tension to return plate 26 to its original position, said plate will be drawn down against abutment 11 on indicator arm 9, and the pawl 27 will strike against said abutment with sufficient force to overcome the tension of spring 32 and release the pawl and permit it to return to its normal position against stop 31. The pawl, in this position, may then be engaged by the ratchet teeth, the position of the movable arm 9 with respect to contact 4L0 controlling the time between alarms.

When it is desired to use the clock merely as a time recording instrument, I adjust the tripper rod 19 to draw the extension 18 and the trip lever 15 into the position shown in dotted lines in Fig. 2. The plate 26 is thus prevented from completing the electrical circuit and the alarm mechanism prevented from being actuated. It will also be noted, by inspection of Fig. 7, that I may turn the ball or knob upon the lower extremity of the screw threaded tripper rod to draw the trip lever from its vertical or natural position and retain same in this position for any length of time, or that the tripper rod may be simply pulled out to permit the skipping of the alarm at a desired interval.

It will thus be seen that I have provided a simple, inexpensive and durable device which may be readily applied to an ordinary clock by securing an extension on the minute hand arbor and which will be of the highest efliciency and will positively operate at the termination of each period of time without necessitating the re-setting of the device, and which is particularly adaptable for use in schools to denote the time to change classes, in shops where certain work requires attention only at statedintervals, permitting the workman to be employed on other work between said intervals and be notified of the time to attend to the other work, or in kitchens to notify the cook when the desired number of minutes have elapsed for the cooking of a certain article, or my clock can be used in schools to sound the periods of classes or recitations; in theaters, to act as a call to the performers, and in fact, in any situation where a signal is desired at certain stated periods of time.

I claim 1. The combination with the minute hand arbor of, a clock, of a ratchet wheel mounted thereon to move therewith, a pawl bearing plate pivotally mounted on the arbor and carrying a pawl adapted to engage the ratchet, a trip lever mounted on the arbor and formed with an abutment adapted to engage and release the pawl, an extension formed on said trip lever, a trip rod connected at one end with said extension, and means connected with said trip rod and operated exteriorly of the clock for causing the trip lever to prevent the movement of the pivotal plate when desired.

2. The combination with the minute hand arbor of a clock, of a ratchet wheel mounted thereon to move therewith, a pawl bearing plate pivotally mounted on the arbor and carrying a pawl adapted to engage the ratchet, a trip lever mounted on the arbor and formed with an abutment adapted to engage and release the pawl, an electric circuit associated with said clock mechanism, one leg of the circuit terminating at a contact point carried by the clock and the other leg terminating at the pivotal plate, an alarm mechanism arranged in said circuit Copies of this patent may be obtained for five cents each, by addressing the and actuated by the engagement of the plate with the contact point, a trip rod connected at one end to the trip lever and carrying a plunger near its other end, a housing for said plunger, a spring surrounding said trip rod and incased in said housing, and an operating member threaded onto the extremity of the trip rod and operable ,from without the clock.

In testimony whereof I aflix my signature in presence of two witnesses.

LEWIS D. GIDDENS.

Witnesses:

R. B. SIMPSON,

H. H. MURRAY.

Commissioner of Iatents.

Washington, D. C. 

